1. Field of the Invention
This invention is in the field of chemical reactor machines for reacting one or more porous solid reactants with one or more gaseous reactants, wherein compression of gaseous reactants into the pore spaces of the solid reactant is followed by expansion of the resultant product gases out of these pore spaces, and this cycle of compression and expansion is repeated.
2. Description of the Prior Art
Examples of prior art reactors for reacting solid reactants with gaseous reactants are described in the following U.S. patents:
U.S. Pat. No. 4,455,837, J. C. Firey, 26 Jun. 1984 PA1 U.S. Pat. No. 4,484,531, J. C. Firey, 27 Nov. 1984 PA1 U.S. Pat. No. 4,509,957, J. C. Firey, 9 Apr. 1985 PA1 U.S. Pat. No. 4,533,362, J. C. Firey. 7 Aug. 1985 PA1 U.S. Pat. No. 4,537,603, J. C. Firey, 27 Aug. 1985 PA1 U.S. Pat. No. 4,568,361, J. C. Firey, 4 Feb. 1986 PA1 U.S. Pat. No. 4,794,729, J. C. Firey, 3 Jan. 1989 PA1 U.S. Pat. No. 4,584,970, J. C. Firey, 29 Apr. 1986 PA1 U.S. Pat. No. 4,692,171, J. C. Firey, 8 Sept. 1987 PA1 U.S. Pat. No. 4,698,069, J. C. Firey, 6 Oct. 1987 PA1 U.S. Pat. No. 4,707,991, J. C. Firey, 24 Nov. 1987
In all of the above example reactors the gaseous reactants are compressed into the pore spaces of the solid reactants located within a reaction chamber inside a pressure vessel container, and this compression is followed by expansion of the primary reacted gases, formed by reaction of reactant gases with solid reactants, out of the pore spaces of the solid reactant. This cycle of compression followed by expansion is repeated. In some of these example gas with solid reactors fresh gaseous reactant is supplied for each compression and product reacted gases are removed during or after each expansion. In other of these example gas with solid reactors several cycles of compression and expansion are applied to a particular gas mass before removing product reacted gases and replacing with fresh reactant gas for the next sequence of cycles of compression and expansion.
Where a reciprocating piston is operated within a cylinder for both compressing and expanding the gases only a single stage of compression and expansion occurs and this is a combined means for compressing and expanding the gases. Where several stages of compression or where several stages of expansion are to be used the means for compressing the gases needs to be separate from the means for expanding the gases. Such separate compressors and separate expanders are herein and in the claims referred to as separate means for compressing and separate means for expanding, even when only one stage is used. The particular definition of a stage of a compressor or an expander is used herein and in the claims to be a portion of said compressor or expander which has a gas flow inlet and a gas flow outlet both of which make connections external from the compressor or expander.
Some means for driving the separate compressor is needed and this can be the separate expander, if an expander engine is used, or some other type of drive engine can be utilized. The net work output rate of a cyclic gas with solid reaction plant is herein defined as the difference between the work output rate of the expander engine and the work input rate to the compressor.
Such chemical reactors for reacting solids with gases and using this cyclic compression and expansion process are herein and in the claims referred to as cyclic gas with solid reaction plants. The descriptions of various such cyclic gas with solid reaction plants contained in the above listed U.S. Patents are incorporated herein by reference thereto.
The term solid reactant is used herein and in the claims to include wholly solid materials as well as solids whose surface is wetted with a liquid. A single solid reactant can be but a single chemical or a mixture of several different chemicals.
The term gas reactant is used herein and in the claims to include single gaseous chemicals as well as mixtures of several different gaseous chemicals which are about to be reacted with a solid reactant.
The term reacted gas is used herein and in the claims to include single gases or mixtures of different gases which have reacted with a solid reactant.
The term changeable gas flow connection is used herein and in the claims to mean a gas flow connection which can be opened or closed while the plant is operating. The term fixed open gas flow connection is used herein and in the claims to mean a gas flow connection which remains open whenever the plant is operating.
In many cyclic solid with gas reaction plants at least two steps of chemical reaction occur: a primary reaction between gas reactant and solid reactant during compression; a secondary reaction between the primary product reacted gas from the primary reaction and additional gas reactant during expansion. The primary reaction takes place principally with the pore spaces of the solid reactant whereas the secondary reaction takes place principally outside the pore spaces of the solid reactant. A volume or space wherein chemical reaction occurs is herein and in the claims referred to as a reaction chamber. For example, the pore spaces within the solid reactant are a primary reaction chamber, whereas any gas space outside this primary reaction chamber may be a secondary reaction chamber if secondary reactions occur there. These primary and secondary reaction chambers may be separately enclosed by the containing walls of separate pressure vessel containers or may be jointly enclosed within the containing walls of a single pressure vessel container.
Where separate compressor and separate expander are used and these perhaps each of several stages, several containers are used whose number at least equals the sum of the number of compressor stages plus the number of expander stages. Each of these several containers is connected in sequence to each outlet of each compressor stage in order of increasing reactant gas pressure and then to each inlet of each expander stage in order of decreasing reacted gas pressure and this sequence of changeable gas flow connections is repeated by each container for each cycle of compression followed by expansion. In this way each compressor outlet and each expander inlet is always connected to one container and each container is always connected to either one compressor outlet or one expander inlet or is undergoing replacement or removal of solid reactant.
In a cyclic velox boiler, as described in U.S. Pat. No. 4,455,837, it is desired to achieve complete burnup of the solid char fuel reactant, contained within the primary reaction chamber. For this complete burnup purpose admission of air, as reactant gas, into the primary reaction chamber during compression is preferably distributed along the length of the primary chamber from the char fuel admission end to the ash removal end. Ash retention within the primary reaction chamber is also desired so that ashes can be removed periodically from the ash removal end. For this ash retention purpose outflow of primary reacted gas from the primary reaction chamber during expansion is preferably only from the char fuel admission end where the char fuel particles are larger and heavier. But the ash particles are smaller than the char fuel particles. Hence, if combined air inflow and gas outflow channels are provided near the ash removal end to secure complete char fuel burnup, the reverse flow of primary reacted gas through these same channels during expansion may carry over ash particles into the expander. This is one example of a problem which the devices of the invention described herein can alleviate.
In a cyclic velox boiler, as described in U.S. Pat. No. 4,455,837 for example, and in a cyclic char gasifier, as described in U.S. Pat. No. 4,509,957 for example, wherein the expander is an engine and is used to drive the compressor, at least in part, the net rate of work output fluctuates at each change of connections of the changeable gas flow connections. This fluctuation of net work output results primarily from the changes of container pressures during each time interval between changes of connections, the pressure in containers being compressed rising during the interval, while the pressure in containers being expanded decreasing during the interval. A description of these fluctuations of net work output is presented in my U.S. Pat. No. 4,509,957 at column 26, lines 27 through 53 and column 38, lines 25 through 51, and this material is incorporated herein by reference thereto. It would be desirable to have cyclic velox boiler plants, cyclic char gasifier plants, and other cyclic solid with gas reaction plants, which did not suffer the disadvantage of these net work output fluctuations.